From b5209277de6cf0a33afe803bfd5eb2fb600a35fe Mon Sep 17 00:00:00 2001
From: edison <daiwei521@126.com>
Date: Tue, 15 Oct 2019 23:59:40 +0800
Subject: [PATCH] refactor(reactivity): define hadKey if necessary (#288)

---
 packages/reactivity/src/baseHandlers.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/reactivity/src/baseHandlers.ts b/packages/reactivity/src/baseHandlers.ts
index 005cb3dd..0043af73 100644
--- a/packages/reactivity/src/baseHandlers.ts
+++ b/packages/reactivity/src/baseHandlers.ts
@@ -38,12 +38,12 @@ function set(
   receiver: any
 ): boolean {
   value = toRaw(value)
-  const hadKey = hasOwn(target, key)
   const oldValue = target[key]
   if (isRef(oldValue) && !isRef(value)) {
     oldValue.value = value
     return true
   }
+  const hadKey = hasOwn(target, key)
   const result = Reflect.set(target, key, value, receiver)
   // don't trigger if target is something up in the prototype chain of original
   if (target === toRaw(receiver)) {